Field Wiring; Figure 9: Typical Installation - Teledyne 700 IR Series Instruction Manual

700 IR Series
INFRARED GAS DETECTOR FOR COMBUSTIBLE AND CO
GASES
USER MANUAL
NOTE: The Teledyne Oldham Simtronics Warranty does not cover water damage resulting from
water leaking into the enclosure. However, since the electronics are 100% epoxy encapsulated,
only the wire terminations could get wet. Moisture could cause abnormal operation and possibly
corrosion to the terminal connections, but permanent damage to the detector would not be
expected.
NOTE: Unused port should be blocked with the M20x1.5 male plug supplied by Teledyne
Oldham Simtronics (ATEX and 'Ex d IIC' certified). The engagement shall be 5 threads at least.
2.7

Field Wiring

Teledyne Oldham Simtronics OLCT 700/710 IR combustible hydrocarbon gas detector
assemblies require three conductor connections between power supplies and host electronic
controller's 4-20mA output, and 2 conductor connections for the Modbus™ RS-485 serial
interface. Wiring designations are + (24VDC), – (0V), mA (detector signal), and Modbus™ RS-
485 A (+), and B (-). Maximum wire length between detector and 24VDC source is shown in the
Table below. Maximum wire size for termination in the Teledyne Oldham Simtronics J-Box
accessory is 14AWG.
Max loop load resistance between green and black wire (analog signal output) is 500 ohms.
Minimum loop load resistance between green and black wire is 100 ohms. This is considers wire
diameter, wire length, max operating temperature and selected termination resistor.
12
2

Figure 9: Typical Installation

Unused port shall be
sealed with the « Ex d »
certified plug delivered
along with the transmitter.
NP700IRIMEN
Revision E.0